This research program was designed to evaluate brain regulation of coitus in the female rat. The studies will differentiate hormone from neural control of behavior by using the ovariectomized and intact animal. Brain regulation of coitus will be studied by using implantation of drugs into specific loci, radiofrequency ablation and partial surgical disruption of fiber systems. Evaluation of physiological processes will be accomplished by monitoring vaginal cycles, counting tubal ova, endocrine gland weights and histology, and radioimmunoassay of gonadotropins and sex steroids where appropriate. Innovative concepts in controlling "aberrant" human sexual behavior establish a need for more knowledge on the neuroendocrine control of copulatory behavior.